Absolutely wonderful. I bought this with the Matrix Magnum 3000 motor, performs like a dream.
First thing I did with it was void the warranty by opening it up. Inside, lots of nice parts. The spring guide stainless steel, as is the cylinder head. Unfortunately, the selector plate did not have contacts, and the wiring set didn't have them for the selector plate either. Wah. Didn't matter, cuz I bought a MOSFET system with a trigger set included, and I had a spare selector plate with trigger contacts. Works very well.
Has what the picture says inside.
Pre-shimmed gears. If you open it up, make sure they don't go flying off so you know where each shim was.
Powerful, well worth the price.
Wiring is extremely short, not even an inch out of the gearbox. If you try to fit it in your lower reciever, the tamiya connecter will probably rip off. It did for me.
No trigger contacts on the selector switch or corresponding ones on the trigger set.
Overall, a very nice gearbox, with a 363mm MadBull V2 6.03mm, madbull ultimate hopup, MOSFET, and this gearbox well outperforming a KWA SR10 without upgrades.
Rating: [5 of 5 Stars!]